Everything you need to know about going vegan

What do Pamela Anderson, Benedict Cumberbatch, Billie Eilish and Venus and Serena Williams all have in common? The answer is they all follow a vegan diet. Over the last 20 years, Dr Phimister has seen a steady increase in the number of patients going vegan. So, if you’re curious about this plant-based diet, got questions about the pros and cons, or swithering about making the switch, read on.

Why has veganism grown in popularity in recent years?

The rise in social media, trends and awareness initiatives such as ‘Veganuary’, coupled with the influencer and celebrity effect, has undoubtedly played a big role in the rise of veganism. But for many vegans, it’s not just about trying to emulate an aspirational celebrity lifestyle. It’s about taking a stand.

Many are compelled to go vegan for ethical reasons – in strong objection to animal cruelty and in support of animal rights, for example. For others, it’s about the ecological impact of a carnivorous diet. We know that pastoral farming results in higher carbon emissions and greater water pollution, and the devastating deforestation in the Amazon rainforest is directly related to farming animals.

For many others, the switch to this plant-based diet is driven by its associated health benefits.

What are the health benefits of going vegan?

According to Dr Phimister, the associated health benefits of following a vegan diet include a lower risk of:

• Colon cancer
• Coronary heart disease
• Obesity
• Non-alcoholic fatty liver disease
• Type 2 diabetes

He also notes that avoiding red meat can help to reduce cholesterol. Plus, cutting out meat means cutting out the consumption of stress hormones and antibiotics found in the meat and products of cows and chickens raised in unnatural living conditions. In addition, there is a lot to be said for avoiding ultra-processed foods such as chicken nuggets and fish fingers.

What are the potential health concerns of going vegan?

Whilst the benefits listed above are certainly compelling, it is important to take a balanced view and consider the potential drawbacks of following a vegan diet. From his experience of treating many patients over the years and research, Dr Phimister highlights the following health concerns to be aware of:

• Vitamin B12 deficiency: This has the potential to lead to issues with the nervous system as well as blood disorders. Lower vitamin B12 levels have also been found in menopausal and postmenopausal breast cancer, cervical and gut cancers.
• Low iron in menstruating women: This can result in fatigue, brain fog, less exercise tolerance, less work and life productivity.
• Lower protein intake: Plant-based proteins are less bioavailable. This may lead to nutritional deficiencies – especially in children, pregnant women and the elderly – where higher protein requirements are needed for health. Sarcopenia or muscle weakness may result.
• Poorer zinc absorption: Zinc absorption is less in vegans due to plant-based phytic acid found in wholegrains, legumes, nuts, which can lead to lower blood and tissue levels, potentially leading to dermatitis, hair loss and depression.
• Vitamin D and calcium deficiency: This can lead to osteoporosis.
• Iodine deficiency: This has the potential to lead to hypothyroidism.
• Omega deficiency: This has the potential to lead to depression.

What health supplements are recommended for vegans?

Given the potential deficiencies listed above, Dr Phimister advises discussing the following with your GP or primary care professional:

• Vitamin B12 injections or tablets, according to blood levels
• Iron supplements, according to blood levels
• Multivitamin supplement
• Omega-3 supplement

And finally…

Being a vegan is a personal choice. Ethical arguments aside, those looking to switch to a purely plant-based diet may do well to consider the scientific evidence pointing to lacto-vegetarians or pescatarians being healthier. Studies have even shown that eating a good quality steak or beef infrequently will help you absorb all the easily absorbed vitamins, minerals and iron.

In addition, Dr Phimister suggests that fermented dairy and non-dairy sources are important food sources of probiotics to support the gut microbiome and health. And that minimising ultra-processed foods is the most critical step in eating for health.

*Studies, references and resources

• Bali A, ‘The Impact of a Vegan Diet on Many Aspects of Health: The Overlooked Side of Veganism’, Cureus, 2023 Feb 18;15(2):e35148.
• Schaafsma G, ‘The protein digestibility-corrected amino acid score’, Journal of Nutrition, 2000;130:1865–1867.
• Agnoli C, ‘Position paper on vegetarian diets from the working group of the Italian Society of Human Nutrition’, Nutrition, Metabolism and Cardiovascular Disease, 2017;27:1037–1052.
• Davey GK, EPIC-Oxford: lifestyle characteristics and nutrient intakes in a cohort of 33 883 meat-eaters and 31 546 non meat-eaters in the UK’, Public Health Nutrition, 2003;6:259–269.
• James H, ‘Debunking the vegan myth: The case for a plant-forward omnivorous whole-foods diet’, Progress in Cardiovascular Diseases, 2022;7:2-8.